Upgrading Junos issue – not enough space

Quick note, mostly for my own reference down the track.

I have in the lab a MPC3E-NG FQ and a MIC3-100G-DWDM card. To those of you not Juniper ensconced, that’s a chassis-wide slot and a 100Gbit/s DWDM (tunable optic) card. Wowee, I hear you say. Anyway, the 100G DWDM card requires a fairly spicy new version of Junos, one with a new underlying FreeBSD core at the heart. My lab was running on Junos 14.1R5.5, an already pretty recent version – but for 100G across my lab I need to use the DWDM card, inconjunction with some Infinera DWDM kit for good measure.

Normally, a Junos upgrade is fairly painless. In this case however, I was getting errors that I couldn’t understand. Here is how I pushed past them.

When going from 14.x to 15.1F6, Juniper don’t recommend running validation of the software release against your config.

This looks a bit like something has gone wrong, but it’s not immediately obvious what it is. I am using a .tgz of Junos 15 that is sitting on my RE1’s /var partition, and it has 2.1 GB hard-drive space free (show system storage)… Queue a few hours of headscratching.

Turns out, my assumption on how much space is actually required when upgrading from Junos 14 to 15 was completely under. I started with about 2GB free, but when I was finally successful I had 11GB free. Once the install was complete, I was down to 7.7G, which means the installation process uses up 3.3GB all by itself. I guess that’s not crazy, as the tarball is 1.9GB to begin with, but the error output didn’t make it clear enough for me, a stupid man.

Here is how I overcame the obvious and got Junos 15.1F6 installed 🙂

1: Jump into shell

james@mxZ.lab.re1> start shell

2: Become root

james@mxZ.lab.re1> su
<enter password>

3: Find all the files that are > 500MB. We’re looking for things in /var

root@mxZ% find / -size +500000

4: Delete any of the old .tgz files from previous releases. If you want to keep them, SCP them off first.